Hidden bookshelf switch

So you don’t have any secret passageways in your house, but if you’ve got a bookshelf this secret switch can add some fun to your routine. [Brandon] saw a commercially available version which was out of stock when he went to order so he set out to build his own.

He’s using the switch to operate a lamp. The donor part for the hack is a lamp dimmer which you’ll find at the big box store. This is really just a pass-through wall plug with an extension cord. By cutting the dimmer module off of the extension a push button can be used to connect and disconnect one of the conductors in the line. Make sure you use a push button rated or mains voltage!

To make the push switch work with a book [Brandon] bend a bracket which will slide into the spine of a hardcover. We love his homemade press brake (angle iron, a sturdy hinge, and a chunk of 2×4) used when shaping the bracket. Once everything’s in place nobody will ever know there’s anything special about those books.

.. and a time delay: you remove the book, put it back, do some other things, and then the relay activates.
i’d hide the reed switch in the shelf and a small magnet in the book. (dollar store sometimes has alarms with reed switches)

Not needed! I got a dirt cheap GE remote power switch, opened the transmitter dongle, wired a small mercury switch across the xmit button, and mounted it in a (thin) book at a 30-40 degree angle. Tip book as in picture, command sent. This concept is best implemented with a push on/push off design of power switch. Since the GE power switch I was given had ON and OFF buttons, another Hg switch tipping the other way was wired to xmit the OFF signal. No wires to run. Finished!

GE engineered and built the AC plug in power switch, not me. It is isolated from my hack by around 10 feet of air, which I say is about the ultimate in protection from AC voltages. So, this hack was totally safe, cheap (as in free),and nothing needed to be built.

I found my Hg switches at an auto salvage yard, where >25 YO cars used them as hood and trunk light switches. Alternatively, small reed switches and a magnet hanging on a string would work too. (You will need to have a thin block to keep magnet from hitting the glass switch, and if allowed to get too close, the magnet might stick to the switch.)

+1 This was also my first thought after reading the article. You could even orient the mercury switch such that you had to remove the book and insert it upsidedown to activate the switch… to thwart people from just tipping them all to find the right one… not that they would know to do so. Probably unnecessary. Like the wireless hack though… you could then very easily change the location of the secret book… move the book itself, or move the transmitter pretty easily to another book (or any physical item).

great. this could be done with any object in the room – and one that is not physically attached to anything.
if anyone wants to do that without digging at the junkyard for mercury: there are mercury-free alternatives with a rolling ball inside. not quite as precise as a mercury switch, but fine for this.

Even better, use a low voltage relay in a workbox mounted correctly in a safe location… running mains voltage into a concealed switch as described in this instructable does not meet code (this would effectively be a permanent installation), and could lead to injury or property damage. The entire instructable, as presently written, leaves you with nothig more than a method to test your circuit breaker (hit the switch, make a short). Not until the final step is there a mention of “connect the cord of your switch to the cord of your lamp…”, but that goes unexplained. In the meantime you’ve been instructed to run your cord with a switch to an outlet (and presumably you might just plug it in and test it).

This one needs to go back to the drawing board for either instruction on proper wiring of a switch into a lamp cord or instruction on how to add a workbox with a relay below the lightswitch that controls your switched outlet ciruit where the lamp is plugged into. In no circumstance should the project, as presently described, be used.

I stand corrected. I went back and re-read and took a better look at the plug end of the cord. I apologize.

This makes for a great temporary installation or for a theater/dorm/display prop. For a permanent installation however, I’m still pretty sure that it’s not code. I could be wrong on that too… stranger things have happened. My inner safety geek would prefer to see the connection-end of the switch in some sort of enclosure instead of just shrinktubing.

I think if I was going to use one of the books from the series in this photo as a secret switch I would have had to use “Chamber of Secrets”. Obvious? Maybe, but that sort of thing is just compulsory where I come….